How to Choose Hay to meet your Horse's Needs

It can be confusing when choosing hay for horses. You will find as many opinions on horse feed as you will horse owners. There are a few important points to consider when choosing hay.

The variety of hay you choose should always come second to the quality of the hay. Hay has to be free of dust, mold, and foreign objects; and it needs to meet your horse's nutritional requirements. Without a doubt the biggest challenge is to find dust free hay. Dust in hay can come from mold spores or leaf shatter. Only in rare occasions does dust come from hay cut along gravel roads or other dusty situations. Molds form when the hay is baled too wet or the hay is improperly stored allowing moisture to enter from the top or from ground up. Dust from leaf shatter occurs when the hay is too dry, causing the hay to be rittle. Mold dust acts as an allergen and can cause inflammation of the respiratory tract in horses. It may cause temporary coughing or with repeat exposure the horse can develop permanent lung damage commonly known as heaves or chronic obstructive pulmonary disease (COPD). This disease is strictly man made by the repeat feeding of dusty hay. The second problem with moldy hay is the possible formation of mycotoxins, which are poisonous compounds produced by molds. Moldy, dusty hay simply should not be fed to horses.

There is no right or wrong hay to feed your horse. Some like alfalfa as horses like the taste so wastage is low. Alfalfa can be a good choice for finicky eaters or horses with high nutritional needs such as lactating mares, growing foals, hard working horses or horses needing to gain weight. Others may choose timothy, crested wheatgrass or intermediate wheatgrass, as they are easy to cure so tend to be dust free. They are also lower in protein and energy so horses with lower nutritional needs such as the mature idle horse or horses in light work won't become fat.

Hay is the most important feed product that you will give your horse so spend time choosing good hay. Hay is important because it makes up the majority of your horse's diet. Hay provides your horse with the required fiber to maintain good digestive tract function. It also provides most of the nutrients that your horse needs. Hay is low in salt and may be deficient in one or more minerals so salt and a mineral supplement should always accompany hay.

Hay also provides one other seldom thought of function: it gives horses something to do. Horses in a pasture will spend up to 17 hours eating. When we feed hay or concentrates the eating time can be reduced significantly. Horses with reduced eating time become bored and can develop vices such as wood chewing.

When looking for the right hay for your horse, keep in mind all the functions of hay: fiber, nutrients and boredom relief.

Try to match it to the horse's nutritional needs as referred to in Table 1. If nutrient rich hay is fed to a horse with low nutritional needs, weight gain will occur. If low nutrient hay is fed to a horse with high nutritional needs then weight loss or poor growth will occur.


Table 1: Horse Nutritional Needs (adapted from National Research Council)

Class of Horse	Minimum Crude Protein (%)	Minimum Calcium (%)	Minimum Phosphorus (%)	Energy (DE) (Mcal/kg)
Mature
Idle	7.2	0.21	0.15	1.8
Light	8.8	0.27	0.19	2.2
Moderate	9.4	0.28	0.22	2.4
Hard	10.3	0.31	0.23	2.55
Pregnant Mares
0 – 8 months	7.2	0.21	0.15	1.8
9 – 11 months	9	0.39	0.29	2.0
Lactating Mares
Foaling to 3 months	12	0.47	0.30	2.35
3 months to weaning	10	0.33	0.20	2.2
Young Stock
Weanlings	13	0.62	0.30	2.6
Yearlings	11	0.40	0.21	2.5
Up to 2 years old	9.5	0.31	0.18	2.2
Other
Elderly*	12	0.30	0.30	1.80
PMU	4	0.21	0.15	1.80
* If problems arise related to aging you can add 7 to 10% fat to the diet

Protein deficiency causes poor growth in young animals, and weight loss and poor performance, endurance and lactation in mature animals. Hay that is too low in protein will need a high protein supplement added to the diet. There are various high-protein supplements that can be used. High protein supplements are usually higher cost. Ultimately it is cheaper to buy hay with an adequate amount of protein. Alfalfa hay generally has a higher protein content than the grass hays, but not always. It depends partly on the maturity of the forage at harvest.

If you purchase hay too high in protein the horse will simply eliminate the excess protein in the form of urea which is then excreted in the urine at no detriment to the horse. As a secondary problem of excess protein the urea is converted into ammonia and can cause irritation to the lungs of horses kept in poorly ventilated barns. Hay with protein levels above the horse's requirements is of no benefit to the horse so try to purchase hay that meets or only slightly exceeds the protein requirements.

Horses with kidney or liver problems may have problems with high protein hay.

Don't confuse energy and protein. Energy is the calorie content of hay and is used for lactation, growth and work. Protein is used primarily for muscle and tissue building.

Including a concentrate in the horse's diet can rectify too little energy in the hay. This concentrate may be oats, corn, barley, commercial feed or a fat supplemented concentrate; it depends entirely on what is available in your area. Insufficient energy in the diet will cause weight loss, low milk production or poor growth of young horses.

Excess energy is stored in the animal as fat. Owners of fat horses often try to solve the problem by restricting the horse's hay intake. While this may seem like a benefit, as you will use less hay, it can lead to problems such as colic or boredom vises such as wood chewing. It is better to buy hay close to the energy needs of the horse and feed more of it than to restrict hay intake.

These two nutrients are dealt with together because it is the ratio between the two that is so important. You want the diet to provide the minimums outlined in Table 1. The ratio should be at least 1.5:1 or 2:1 ratio. That means 1.5 or 2 parts calcium to 1 part phosphorus. Alfalfa hay will be higher in calcium than the grass hays. Oats is very low in calcium but higher in phosphorous and will have a ratio that is opposite to what you need. If feeding a high grain diet you may need to purchase a 2:1 or even 3:1 mineral mix to get the ratio back in order. Mineral mixes are the easiest way to correct Ca:P balance as well as providing other crucial micro-nutrients.

You will also notice that hay may have Ca:P ratios as high as 8:1. This shouldn't be a concern except with young growing horses where the preferred ratio is 1.5:1 to 3:1. However no detrimental effects have been reported in growing horses fed wider Ca:P ratios as long as sufficient amounts of phosphorus are eaten daily. Make sure your horse is getting the minimums recommended in Table 1.

Buy from a reputable hay grower and build a relationship. Hay growers need constructive feedback in order to provide the product you seek.

When purchasing hay it is best to work the cost out to cents per pound. That way you can compare the true cost of different sized bales. Hay is often priced per bale with no account for bale weight. Which is the best deal a bale for $2.50 or a bale for $3.25? Without the weight the price is meaningless. Both of these bales work out to the same cost per pound as the first bale weighed 58 pounds and the second bale weighed 75 pounds.

Remember that weather conditions have a big influence on hay production, haying conditions and nutrient status. Hay can vary widely from variety to variety, one year to the next, maturity at harvest, or even two cuttings of the same variety on the same field. Good hay growers will be able to provide you with a feed analysis for each lot of hay. Take this analysis to your local feed store, veterinarian, or horse specialist for advice on the correct mineral mix and concentrate supplementation. This way you can ensure proper nutrition for your horse without added costs associated with over or under supplementation.